Many thanks for the authors for presenting this interesting idea. However, some points have to be taken into your consideration:
1- Provide full details of the samples used in the current study including their number, season and area of collection, type of amphipodes (taxonomic classification)..............etc . for both samples collected in 2019 and 2021.
Not accepted to refer to your previously published article in the sample section.
2- Describe the methods used briefly and you can refer to your previously published article in this part.
3- Add a separate section for the statistical analysis.
4- It would be very interesting if the authors could correlate the changes in the microbiome with time passed since 2019 to 2021.
5- The authors should mention the effect of the host on the metacercariae microbiome, if the authors used different species of amphipode host (which is not shown).
6- I felt that the research question is not answered adequately, whether the microbiome content is just an association or it is a causal relationship for the change in the life cycle of C. parvum.
7- Tables should be provided as main results (not as supplementary files).
8- Mention your conclusions clearly at the end of the manuscript.

Thanks for the authors for their response. But as in my previous comment (6), we still couldn't say that your hypothesis is proved or not. As you indicated in the conclusion (line 255) that there were slightly different microbiomes. How can we say that this slight change has proved your hypothesis?